Helmet-integrated weld travel speed sensing system and method

ABSTRACT

A welding system includes a first sensor associated with a welding helmet and configured to sense a parameter indicative of a position of a welding torch relative to the welding helmet. The travel speed sensing system also includes a processing system communicatively coupled to the first sensor and configured to determine a position of the welding torch relative to a workpiece based on the sensed first parameter.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/369,474, filed Dec. 5, 2016, which is a continuation of U.S. patentapplication Ser. No. 13/755,984, entitled “Helmet-Integrated Weld TravelSpeed Sensing System and Method,” filed Jan. 31, 2013, which claimspriority to and benefit of U.S. Patent Application No. 61/597,556,entitled “Weld Travel Speed Sensing Systems and Methods,” filed Feb. 10,2012, each of which is herein incorporated by reference.

BACKGROUND

The invention relates generally to welding systems, and, moreparticularly, to sensing systems for monitoring a travel speed of awelding torch during a welding operation.

Welding is a process that has become ubiquitous in various industriesfor a variety of types of applications. For example, welding is oftenperformed in applications such as shipbuilding, aircraft repair,construction, and so forth. While these welding operations may beautomated in certain contexts, there still exists a need for manualwelding operations. In some manual welding operations, it may bedesirable to monitor weld parameters, such as the travel speed of thewelding torch, throughout the welding operation. While the travel speedof an automated torch may be robotically controlled, the travel speed ofthe welding torch in manual operations may depend on the operator'swelding technique and pattern. Unfortunately, it may be difficult tomeasure this weld motion during a welding operation due to features ofthe welding environment, operator considerations, and so forth.

BRIEF DESCRIPTION

In a first embodiment, a welding system includes a first sensorassociated with a welding helmet and configured to sense a parameterindicative of a position of a welding torch relative to the weldinghelmet. The travel speed sensing system also includes a processingsystem communicatively coupled to the first sensor and configured todetermine a position of the welding torch relative to a workpiece basedon the sensed first parameter.

In another embodiment, a travel speed sensing system includes an opticalsensor disposed on a welding helmet and configured to sense a firstparameter indicative of a position of a welding torch relative to thewelding helmet and a second parameter indicative of a position of acomponent in a weld area. The travel speed sensing system also includesa processing system communicatively coupled to the optical sensor andconfigured to determine a travel speed of the welding torch based on thefirst and second sensed parameters.

In a further embodiment, a travel speed sensing system includes a sensordisposed in a welding helmet and configured to identify an actionperformed by a welding operator wearing the welding helmet. The travelspeed sensing system also includes a processing system communicativelycoupled to the sensor and configured to determine a travel speed of thewelding torch based on a time between the actions identified by thesensor.

DRAWINGS

These and other features, aspects, and advantages of the presentinvention will become better understood when the following detaileddescription is read with reference to the accompanying drawings in whichlike characters represent like parts throughout the drawings, wherein:

FIG. 1 is a block diagram of an embodiment of a welding system utilizinga welding torch;

FIG. 2 is a block diagram of an embodiment of the welding system of FIG.1 , including a travel speed sensing system for detecting a travel speedof the welding torch;

FIG. 3 is a perspective view of an embodiment of the welding system ofFIGS. 1 and 2 , including a welding helmet with associated sensors fordetermining weld travel speed of the welding torch;

FIG. 4 is a block diagram of an embodiment of the travel speed sensingsystem of FIG. 2 , including a sensor module disposed on a weldinghelmet for determining weld travel speed of the welding torch;

FIG. 5 illustrates an embodiment of a display in the welding helmet ofFIG. 3 for displaying weld travel speed related parameters to a weldingoperator;

FIG. 6 is a perspective view of an embodiment of the welding system ofFIG. 2 , including a microphone disposed on a welding helmet fordetermining a travel speed of the welding torch based on a sensedwelding operator voice; and

FIG. 7 is a block diagram of an embodiment of an inertial sensing systemthat may be used to determine a weld travel speed of a welding torch.

DETAILED DESCRIPTION

As described in detail below, provided herein are systems and methodsfor determining the travel speed of a welding device during a weldingoperation. The foregoing systems and methods may be used separately orin combination to obtain information during the welding operationrelating to the three dimensional speed of the welding torch along thesurface of the metal as the metal is being welded. In some embodiments,these methods may be utilized during unconstrained or manual weldingoperations to offer advantages over traditional systems in which it maybe difficult to measure the weld motion. However, the foregoing systemsand methods may be utilized in a variety of suitable welding systems,such as automated or robotic systems.

Present embodiments are directed toward systems and methods for sensinga travel speed of a welding torch using a helmet-integrated system. Morespecifically, the disclosed systems include a travel speed sensingsystem that monitors a parameter associated with the welding system viaa sensor associated with a welding helmet worn by an operator. The term“associated” in this context may refer to the sensor being disposed on,physically coupled to, or in communication with the welding helmet. Theparameter is indicative of a travel speed of a welding torch used in thewelding system, and the travel speed sensing system is configured todetect a position and an orientation of the welding torch relative to aworkpiece based on the monitored parameter. The travel speed sensingsystem may determine various parameters from the determined position andorientation, such as the travel speed of the welding torch.

In some embodiments, the sensor associated with the welding helmet maybe utilized to monitor a position of the welding torch relative to thewelding helmet. Such embodiments may also include one or more sensorsfor monitoring a position of the welding helmet, and the travel speedsensing system is configured to determine or detect the travel speedbased on both monitored positions. In other embodiments, a sensordisposed on the welding helmet may acquire images of a weld area. Thetravel speed sensing system may process the acquired images to determineboth a position of the welding torch relative to the welding helmet anda position of a stationary component in the weld area relative to thehelmet. Based on the two relative positions, the travel speed sensingsystem is configured to determine or detect the position and orientationof the welding torch relative to the component in the weld area, and/orthe travel speed, based on these monitored positions. In still otherembodiments, a sensor disposed on the welding helmet may send a signalbased on an operator-performed action, such as a sound from theoperator, to determine the position of the welding torch. Specifically,the sensor may be a microphone used to identify sounds or words spokenby the operator when the welding torch passes by identifying marks on awelding workpiece. By monitoring changes in position of the weldingtorch via a sensor associated with the welding helmet, the travel speedsensing system may determine a change in spatial location of the weldingtorch with respect to time. The welding operator maintains anunobstructed view of the welding torch via the welding helmet, ensuringa consistent line of sight for the sensor associated with the weldinghelmet for determining the welding torch position.

Similar techniques may be applied to determine other information relatedto a position of the welding torch with respect to the weldingenvironment, based on parameters (e.g., position and orientation of thewelding torch relative to the workpiece) monitored via ahelmet-associated sensor. That is, in addition to or in lieu ofdetermining travel speed of the welding torch, the travel speed sensingsystem may be configured to determine a work angle of the welding torch,a travel angle of the welding torch, a travel direction of the weldingtorch, a tip-to-work distance of the welding torch, proximity of theweld to the joint of the workpiece, or some combination thereof. Each ofthese parameters may be utilized separately or in combination toevaluate weld quality. To determine such information, it may bedesirable for the travel speed sensing system to know where the joint islocated so that the position and orientation of the welding torchrelative to the joint may be determined. This may involve applying acalibration procedure in some embodiments. In other embodiments, thejoint may be positioned relative to sensors of the travel speed sensingsystem before the welding is performed.

Turning now to the figures, FIG. 1 is a block diagram of an embodimentof a welding system 10 in accordance with the present techniques. Thewelding system 10 is designed to produce a welding arc 12 on a workpiece14. The welding arc 12 may be of any type of weld, and may be orientedin any desired manner, including MIG, metal active gas (MAG), variouswaveforms, tandem setup, and so forth. The welding system 10 includes apower supply 16 that will typically be coupled to a power source 18,such as a power grid. Other power sources may, of course, be utilizedincluding generators, engine-driven power packs, and so forth. In theillustrated embodiment, a wire feeder 20 is coupled to a gas source 22and the power source 18, and supplies welding wire 24 to a welding torch26. The welding torch 26 is configured to generate the welding arc 12between the welding torch 26 and the workpiece 14. The welding wire 24is fed through the welding torch 26 to the welding arc 12, melted by thewelding arc 12, and deposited on the workpiece 14.

The wire feeder 20 will typically include control circuitry, illustratedgenerally by reference numeral 28, which regulates the feed of thewelding wire 24 from a spool 30, and commands the output of the powersupply 16, among other things. Similarly, the power supply 16 mayinclude control circuitry 29 for controlling certain welding parametersand arc-starting parameters. The spool 30 will contain a length ofwelding wire 24 that is consumed during the welding operation. Thewelding wire 24 is advanced by a wire drive assembly 32, typicallythrough the use of an electric motor under control of the controlcircuitry 28. In addition, the workpiece 14 is coupled to the powersupply 16 by a clamp 34 connected to a work cable 36 to complete anelectrical circuit when the welding arc 12 is established between thewelding torch 26 and the workpiece 14.

Placement of the welding torch 26 at a location proximate to theworkpiece 14 allows electrical current, which is provided by the powersupply 16 and routed to the welding torch 26, to arc from the weldingtorch 26 to the workpiece 14. As described above, this arcing completesan electrical circuit that includes the power supply 16, the weldingtorch 26, the workpiece 14, and the work cable 36. Particularly, inoperation, electrical current passes from the power supply 16, to thewelding torch 26, to the workpiece 14, which is typically connected backto the power supply 16 via the work cable 36. The arcing generates arelatively large amount of heat that causes part of the workpiece 14 andthe filler metal of the welding wire 24 to transition to a molten state,thereby forming the weld.

To shield the weld area from being oxidized or contaminated duringwelding, to enhance arc performance, and to improve the resulting weld,the welding system 10 also feeds an inert shielding gas to the weldingtorch 26 from the gas source 22. It is worth noting, however, that avariety of shielding materials for protecting the weld location may beemployed in addition to, or in place of, the inert shielding gas,including active gases and particulate solids.

Presently disclosed embodiments are directed to a welding helmet-basedtravel speed sensing system used to detect a change in position of thewelding torch 26 over time throughout the welding process. In someembodiments, the travel speed of the welding torch 26 may refer to achange in three dimensional position of the welding torch with respectto time. In other embodiments, the travel speed of the welding torch 26may refer to a change in two dimensional position of the welding torch26 within a plane parallel to a welded surface of the workpiece 14.Although FIG. 1 illustrates a gas metal arc welding (GMAW) system, thepresently disclosed techniques may be similarly applied across othertypes of welding systems, including gas tungsten arc welding (GTAW)systems and shielded metal arc welding (SMAW) systems. Accordingly,embodiments of the welding helmet-based travel speed sensing systems maybe utilized with welding systems that include the wire feeder 20 and gassource 22 or with systems that do not include a wire feeder and/or a gassource, depending on implementation-specific considerations.

FIG. 2 is a block diagram of an embodiment of the welding system 10,including a travel speed sensing system 50 in accordance with presentlydisclosed techniques. The travel speed sensing system 50 may include,among other things, a travel speed monitoring device 52 configured toprocess signals received from one or more sensors 54 incorporated with awelding helmet 56. The welding helmet 56 is worn by an operator usingthe welding torch 26. The sensors 54 incorporated with the weldinghelmet 56 may be utilized to determine a position of the welding torch26 relative to the welding helmet 56.

The sensors 54 may be any desirable type of sensor that produces anelectrical signal indicative of a position of the welding torch 26within a weld area 58. For example, the sensors 54 may include an arrayof microphones disposed on the welding helmet 56 and configured todetect a sound emitted from a sound source 60. The sound source 60 mayinclude the welding arc 12, a sound emitter disposed on the weldingtorch 26, or any other sound source 60 indicative of a position of thewelding torch 26 operating in the weld area 58. In other embodiments,the sensors 54 may include one or more optical sensors disposed on thewelding helmet 56 and configured to sense a marking 62 indicative of aposition of the welding torch 26. Alternatively, the optical sensor(s)on the welding helmet 56 may be configured to sense a light emitted froma light source 63 (e.g., welding arc 12) of the welding torch 26. Instill other embodiments, the one or more sensors 54 may include amicrophone disposed in the welding helmet 56 and configured to identifyan operator voice 64 indicative of welding torch position. In furtherembodiments, the one or more sensors associated with the welding helmet56 may include a sensor 66 (e.g., a sound sensor) disposed on thewelding torch 26 and configured to monitor a sound output from a soundsource 68 located on the welding helmet 56. Other types of sensors maybe associated with the welding helmet 56 to help determine position ofthe welding torch 26.

The one or more sensors 54, 66 may send signals 70 indicative of weldingtorch position to the travel speed monitoring device 52. In someembodiments, the travel speed sensing system 50 may include additionalsensors 72 at a fixed location relative to the workpiece 14. Theseadditional sensors 72 may be used to determine a position andorientation of the welding helmet 56 relative to the workpiece 14. Insome embodiments, for example, the welding helmet 56 may include amarking 73 that may be detected via the sensors 72 to determine aposition or orientation of the welding helmet 56. The sensors 72 maysend signals 74 indicative of this position to the travel speedmonitoring device 52. The travel speed monitoring device 52 may thendetermine a position of the welding torch 26 based on both the monitoredposition/orientation of the welding torch 26 (relative to the weldinghelmet 56) and the monitored position/orientation of the welding helmet56 (relative to the sensors 72). That is, the travel speed sensingsystem 50 may receive the signals 70 and the signals 74, and determinethe travel speed of the welding torch 26 based on these signals 70 and74.

As noted above, the sensors 72 may be positioned stationary with respectto the workpiece 14 during welding. Different methods may be applied todetermine, or ensure the consistency of, the position and orientation ofthe sensors 72 relative to the workpiece 14. In some embodiments, theworkpiece 14 may be placed in any spatial relationship to the sensors72, and a calibration scheme may be applied via the weld travel speedsystem 50. For example, the welding torch 26 may be placed at one ormore known positions relative to the workpiece 14, and sensormeasurements taken at these positions may be used to calibrate thespatial relationship between the workpiece 14 and the sensors 72. Inother embodiments, a fixture or marking in the weld area 58 may indicatea location for the workpiece 14 to be placed relative to the sensors 72(or vice versa). The travel speed sensing system 50 may be designed toaccount for this particular relative placement of the workpiece 14 andthe sensors 72.

The weld area 58 may include a weld cell within which a welding operatoruses the welding torch 26 to perform a welding operation. In someembodiments, the weld area 58 may include a surface or structure uponwhich the workpiece 14 is located throughout the welding process, or theworkpiece 14 itself. The weld area 58 may include any three-dimensionalspace within which a welding operation is performed via the weldingsystem 10.

As shown, the travel speed monitoring device 52 may include a processor76, which receives inputs such as sensor data from the sensors 54, 66and/or the sensors 72 via their respective signals 70 and 74. Eachsignal may be communicated over a communication cable, or wirelesscommunication system, from the one or more sensors 54, associated withthe welding helmet 56. In an embodiment, the processor 76 may also sendcontrol commands to a control device 78 of the welding system 10 inorder to implement appropriate actions within the welding system 10. Forexample, the control device 78 may control a welding parameter (e.g.,power output, wire feed speed, gas flow, etc.) based on the determinedtravel speed of the welding torch 26. The processor 76 also may becoupled with a display 80 of the travel speed monitoring device 52, andthe display 80 may provide a visual indicator of the travel speed of thewelding torch 26 based on the determined travel speed. In certainembodiments, the processor 76 may be coupled with a display 82 in thewelding helmet 56, wherein the display 82 is used to provide visualindicators of the travel speed of the welding torch 26 directly to thewelding operator as the operator is performing the weld. The processor76 may receive additional sensor feedback 84 from the welding system 10,in order to monitor other welding parameters. These other weldingparameters may include, for example, a heat input to the workpiece 14.

The processor 76 is generally coupled to a memory 86, which may includeone or more software modules 88 that contain executable instructions,transient data, input/output correlation data, and so forth. The memory86 may include volatile or non-volatile memory such as magnetic storagememory, optical storage memory, or a combination thereof. Furthermore,the memory 86 may include a variety of machine readable and executableinstructions (e.g., computer code) configured to provide a calculationof weld travel speed, given input sensor data. Generally, the processor76 receives such sensor data from the one or more sensors 54, 66associated with the welding helmet 56, and references data stored in thememory 86 to implement such calculation. In this way, the processor 76is configured to determine a travel speed of the welding torch 26, basedat least in part on the signals 70.

In some embodiments, the travel speed sensing system 50 may be providedas an integral part of the welding system 10 of FIG. 1 . That is, thetravel speed sensing system 50 may be integrated into a component of thewelding system 10, for example, during manufacturing of the weldingsystem 10. For example, the power supply 16 may include appropriatecomputer code programmed into the software to support the travel speedsensing system 50. However, in other embodiments, the travel speedsensing system 50 may be provided as a retrofit kit that may enableexisting welding systems 10 with the helmet-integrated travel speedsensing capabilities described herein. The retrofit kit may include, forexample, the travel speed sensing system 50, having the processor 76 andthe memory 86, as well as one or more sensors 54 from which the travelspeed sensing system 50 receives sensor input. In some embodiments, theretrofit kit may also include the welding helmet 56 having the sensors54, display 82, sound source 68, and/or marking 73 installed thereon, inaddition to the welding torch 26 having the sensor 66, sound source 60,light source 63, and/or marking 62 installed thereon. To that end, suchretrofit kits may be configured as add-ons that may be installed ontoexisting welding systems 10, providing travel speed sensingcapabilities. Further, as the retrofit kits may be installed on existingwelding systems 10, they may also be configured to be removable onceinstalled.

FIG. 3 is a perspective view of an embodiment of the welding system 10capable of monitoring a position of the welding helmet 56 to determinethe travel speed of the welding torch 26. In the depicted welding system10, an operator 110 is wearing the welding helmet 56 while welding.External helmet position detection sensors 112 are located near theoperator 110 to assess the position and orientation of the weld helmet56. As noted previously, the welding helmet 56 may be augmented withmarkings 73 (e.g., visual markings 114 and 116), transducers, or sensorsthat operate in conjunction with the external helmet position detectionsensors 112 to enable the position and orientation of the welding helmet56 to be tracked during the welding operation. In some embodiments, themarkings 73 used to determine the location of the welding helmet 56 mayalso include geometric features or edges 118 used as indicia for helmetposition and orientation determination. One or more sensors (e.g.,sensors 54) or transducers on the welding helmet 56 may then be used tolocate the relative position or motion of the welding torch 26, thewelding arc 12, or a sensor/transducer/target 120 (e.g., marking 62) onthe welding torch 26. In certain embodiments, by combining the motion ofthe welding helmet 56 with the relative motion of the welding torch 26,the travel speed sensing system 50 may calculate the weld travel speedof the welding torch 26 relative to the workpiece 14.

It should be noted that the sensors 112 may include, or be replaced by,any method or device capable of detecting the position of the weldinghelmet 56. For example, the sensors 112 may include a stereo visioncamera located overhead to determine the location and orientation of thewelding helmet 56. Another stereo vision camera may be located on thewelding helmet 56 (e.g., sensors 54) to locate the relative position ofthe welding arc 12. The sensors 112 may include optical sensors fordetermining the position of the welding helmet 56 by determining aposition of a predefined point, such as the markings 114, 116, or theedge 118, on the welding helmet 56. The markings 114, 116 may includepassive visual markings that reflect light, or active visual markingsthat include infrared LEDs. In some embodiments, in order to providereliable weld travel speed estimates, the helmet location determinationmay be supplemented with a measure of an orientation 122 inthree-dimensions of the welding helmet 56 (three orthogonal rotationangles defining the helmet direction). The orientation may be visuallydetermined, for example, via helmet markings (e.g., markings 114, 116)or geometric features (e.g., edge 118) detected by a plurality of cameraimagers external to the welding helmet 56. Additionally, in anotherembodiment, the orientation 122 may be obtained from sensors 124 (e.g.,inclinometers, triaxial accelerometers, etc.) mounted to the weldinghelmet 56.

In still other embodiments, the sensors 112 may include a single opticalsensor configured to detect structured light projected onto the weldinghelmet 56 from a light source external to the welding helmet 56. Thelight source may include a point source at a fixed location relative tothe camera (sensor 112). The light source may project a grid or otherstructured pattern toward the welding helmet 56. Wherever the patternstrikes the welding helmet 56, the light may produce a patternindicative of the shape and distance of the welding helmet 56 from thecamera. As the light hits the welding helmet 56 from different angles,the projected grid may become distorted based on the contours of thewelding helmet 56. The welding helmet 56 may be shaped such that thedistorted grid may be utilized to identify a position, distance, andorientation of the welding helmet 56 via image processing of imagesacquired via the camera. The structured light could include an array ofpoints, circles, stripes, or any desirable collection of light patternsthat can be recognizable.

There may be any number of techniques used to determine a position ofthe welding torch 26 relative to the welding helmet 56 over time. Forexample, in some embodiments the sensors 54 disposed on the weldinghelmet 56 may include a microphone array disposed on the welding helmet56 and configured to monitor a sound output from the welding torch 26.The sound may be emitted from a sound emitter disposed on the weldingtorch 26, or the sound may come directly from the welding arc 12generated by the welding torch 26. In another embodiment, the sensors 54may include any desirable optical sensor configured to detect lightemitted from the arc 12 produced by the welding torch 26, or to detect atarget 120 disposed on the welding torch 26.

In other embodiments, the sensors associated with the welding helmet 56may be located on the welding torch 26 and configured to communicatewith the welding torch 26 (e.g., via one or more emitters disposed onthe welding torch 26). More specifically, the sensors 54 may be replacedaltogether with one or more sound emitters (e.g., sound source 68) tooutput sound toward the welding torch 26. In such embodiments, thewelding torch 26 is equipped with one or more sensors 66 configured todetect when one or more sounds emitted from the welding helmet 56 reachthe welding torch 26. The travel speed monitoring device 52 may use timeof flight trilateration methods to determine travel speed of the weldingtorch 26 based on the detected sounds. Similarly, the welding helmet 56may be equipped with one or more light emitters, or a target (similar toor same as the markings 114, 116). The one or more sensors 66 on thewelding torch 26 may include optical sensors for detecting changes inthe emitted light, or the markings. The travel speed sensing system 50may then determine a position of the welding torch 26 relative to thewelding helmet 56 based on the detected light or images.

Regardless of the method utilized to determine the helmet location andorientation, the sensors 54 or emitters (e.g., sound source 68) may beplaced on the side of the welding helmet 56 facing the weld that willallow the relative position of the welding torch 26 to be measured.Techniques discussed above, including a microphone array to locate theweld arc sound (or other emitted sound), a stereo vision camera totriangulate the welding arc 12, and an emitter array with a sound sensoron the welding torch 26, may all be fitted onto the welding helmet 56 totrack the position of the welding torch 26.

In some embodiments, the welding helmet 56 may include an optical sensor(e.g., camera) configured to sense a first parameter indicative of aposition of the welding torch 26 relative to the welding helmet 56 and asecond parameter indicative of a position of a component in the weldarea 58. The travel speed sensing system 50 may determine the travelspeed of the welding torch 26 based on these first and second monitoredparameters. This travel speed determination may be based on a determinedposition and orientation of the welding torch relative to the componentin the weld area. The component in the weld area 58 may include theworkpiece 14 or any other component that is substantially stationarywithin the weld area 58 and within a line of sight of the welding helmet56. In such instances, the workpiece 14 (or other component) may beprepared with one or more visual features 126 used for weld travel speeddetermination. The features 126 may be planar visual markings, so thatthe images collected may provide information related to position andorientation of the component relative to the welding helmet 56. Thefeatures 126 may be applied to the workpiece 14 via a rubber stamp, suchthat the stamped feature 126 reflects visible light. In someembodiments, multiple features 126 may incrementally mark off a specificdistance along an edge of the workpiece 14. The optical sensors 54(e.g., camera) on the welding helmet 56 may sense the features 126 onthe workpiece 14 along with the target 120 on the welding torch 26. Thetravel speed monitoring device 52 may then utilize any desirable imageprocessing scheme to determine weld travel speed from changes inrelative position of the welding torch 26 versus the features 126.

Other suitable techniques, not discussed above, may be utilized tomeasure the relative welding torch position given the proximity andguaranteed line or sight of the welding helmet 56 to the welding torch26. As an example, FIG. 4 is a block diagram of an embodiment of thetravel speed sensing system 50, including a sensor module 130 disposedon the welding helmet 56 for determining weld travel speed of thewelding torch 26 relative to the welding helmet 56. The sensor module130 may be equipped with both an emitter 132 and a corresponding sensor134. The illustrated emitter 132 is configured to emit a light,structured light pattern, sound, wavelength of energy, or otherdetectable signal 136 toward the weld area 58. Similarly, the sensor isconfigured to detect a portion 138 of the signal 136 that is reflectedfrom a surface of the welding torch 26. As the welding torch 26 is movedrelative to the welding helmet 56 (e.g., arrow 140), the portion 138 ofreflected signal may change based on the changing surface of the weldingtorch 26. Based on the detected reflection, the travel speed monitoringdevice 52 may determine a position of the welding torch 26 relative tothe welding helmet 56. The sensor module 130 may utilize techniquesincluding, but not limited to, radar, LIDAR, ultrasonic echo location,pattern recognition, and modulated light intensity. The sensor module130 maintains a relatively consistent line of sight to the welding torch26 throughout a welding operation, as the operator 110 moves the weldinghelmet 56 to track the progress of the weld.

As noted above with respect to FIG. 2 , the travel speed sensing system50 may include a display 82 located in the welding helmet 56, configuredto display parameters related to the weld travel speed of the weldingtorch 26. FIG. 5 illustrates an embodiment of the display 82, showingsome parameters that may be displayed to the operator 110. The weldingsystem 10 may be equipped to provide an augmented reality view of theweld area 58 via the display 82 of the welding helmet 56. That is, thewelding helmet 56 may be configured to display, in addition to or inlieu of the actual welding environment as visible from the weldinghelmet 56, an augmented visualization of one or more reference pointswithin the weld area 58. The augmented visualization may provide visualguides to direct the operator 110 to move the welding torch 26 at anappropriate travel speed for inputting a desired amount of heat to theworkpiece 14.

In some embodiments, the travel speed sensing system 50 may determine aplane of reference based on sensor information (e.g., from a cameramounted on the welding helmet 56), and display the plane of reference onthe display 82. This plane of reference may, in some embodiments,include an image of the entire weld area 58, including the workpiece 14and the welding torch 26. In other embodiments, the display 82 mayinclude a spatial representation of the welding joints of the workpiece14, such as the T-joint intersection shown in FIG. 5 . Any part of theconstructed image that is blocked from view, or otherwise not accessibleto the camera, may be extrapolated into the image formed via the display82 based on the available image data.

The display 82 may overlay the image of the workpiece 14, as seenthrough the welding helmet 56, with certain marks, lines, blinkingpoints, etc., to indicate a desired weld travel speed for the operator110 to track with the welding torch 26. The display 82 may show, forexample, an arrow 150 that moves in the direction of the weld 152 at thedesired weld travel speed. This weld travel speed may be determined viathe travel speed monitoring device 52, based on voltage and currentmeasurements taken from the power supply 16 (via sensor feedback 84) andbased on the configuration of the workpiece 14 and the weldingapplication. Changing the weld travel speed affects the amount of heatinput to the workpiece 14, so it may be desirable for the display 82 toprovide a visualization corresponding to a desirable weld travel speedfor providing the correct amount of heat to the workpiece 14. In otherembodiments, the display 82 may show incremental markings 154 on theworkpiece 14 to help the operator 110 control the pace of welding. Suchmarkings 154 may be overlaid onto the image provided via the display 82,or the workpiece 14 itself may be prepared with the markings 154. If themarkings 154 are present on the actual workpiece 14, the markings 154could be passive or reflective markers, or they could be infrared LEDs,blinking markers, stamps, electronic ink, or any other suitable form ofmarker that could be applied to the workpiece 14. The display 82 mayprovide one or more blinking indicators 156 that are shown on thedisplay and configured to blink whenever the welding torch 26 shouldpass the next incremental marking 154 to maintain the desired weldtravel speed.

In certain other embodiments, the augmented reality available throughthe welding helmet 56 may provide indicators (e.g., textual or visual)to the operator 110 to describe how the operator 110 should adjust theweld travel speed of the welding torch 26. For example, the travel speedmonitoring device 52 may determine the current travel speed of thewelding torch 26, determine a desired travel speed of the welding torch26 based on the sensor feedback 84 discussed above, and compare the weldtravel speeds. If the monitored travel speed of the welding torch 26 istoo fast or too slow, the display 82 may provide appropriate indicatorsto notify the operator 110 during the welding process.

As mentioned above with respect to FIG. 2 , the sensors 54 incorporatedwith the welding helmet 56 may include a microphone 170 configured todetect an audible signal from the operator's voice 64. A perspectiveview of one such embodiment of the welding system 10 is provided in FIG.6 . In this embodiment, the workpiece 14 includes markings 154 that werepreviously applied to the joint area that is visible to the operator 110during welding. Throughout the welding operation, the operator 110 maygive an audible indication when the weld 152 or the welding torch 26reaches each marking 154. The travel speed sensing system 50 maydetermine the weld travel speed of the welding torch 26 based on thetiming of each audible signal given by the operator 110.

In the illustrated embodiment, the markings 154 are applied to each ofthe two workpieces 14 that are being welded together, however in otherembodiments the markings 154 may be applied to just one side. As notedabove, these markings 154 may include any suitable marking for preparingthe workpiece 14, such as reflective markers, passive markers, infraredLEDs, and/or electronic ink markers. Regardless of the type of markerused, it is desirable for the markings 154 to be capable of withstandinghigh heat associated with the welding application. The operator 110 maysay an identifiable word (e.g., “mark”) when each incremental marking154 is reached. The microphone 170 may wirelessly transmit the detectedsound signal to the travel speed monitoring device 52 for processing.Based on the timing of each identifiable word in the signal, the travelspeed monitoring device 52 may determine the weld travel speed of thewelding torch 26. Because this embodiment of the travel speed sensingsystem 50 relies on the operator 110 identifying the markings 154, itmay be unlikely for weld travel speed determination to be compromiseddue to sensors being out of a line of sight of the welding event. Inaddition, there is no need for additional sensors to determine aposition of the welding helmet 56.

Other techniques for indicating the travel speed of the welding torch 26may be implemented through actions of the operator 110. For example, insome embodiments, the operator 110 may apply pressure to a pressuresensor disposed in the welding helmet 56. The pressure sensor may detecta pressure applied to a pacifier via the operator's mouth, or a pressureapplied to a jaw strap via the operator's jaw movements. In otherembodiments, the operator 110 may depress a button 172 disposed on thewelding torch 26 whenever the welding torch 26 or the welding arc 12pass by one of the markings 154. The travel speed monitoring device 52may then determine weld travel speed based on the timing of eachdepression of the button 172.

In some embodiments, the markings 154 may include blinking indicators(e.g., infrared LEDs) that blink at a pace indicative of a target weldtravel speed. That is, the markings 154 may blink at a pace at which thewelding torch 26 should be passing each of the markings 154. This targettravel speed may be determined based on monitored voltage, current, anddesired heat input for the welding application. In further embodiments,the desired pace may be indicated to the operator 110 through othermethods. For example, the welding helmet 56 may be equipped with a soundemitter 174 configured to provide an audible indication to the operator110 for the pace at which the welding torch 26 should pass each of themarkings 154.

It should be noted that a variety of other methods and devices may alsobe employed to determine the travel speed of the welding torch 26 overtime during a welding operation. For example, in an embodiment, aninertial sensing technique may be utilized. One such embodiment isillustrated as a block diagram in FIG. 7 . In the illustratedembodiment, an inertial sensing module 190 is disposed in the weldingtorch 26. The inertial sensing module 190 may perform inertial sensingof torch position using combinations of accelerometers 192 andgyroscopes 194 to sense up to approximately six degrees of freedom ofmotion. By utilizing the accelerometers 192 and gyroscopes 194 todetermine the acceleration of the welding torch 26, the speed can beobtained by integrating the acceleration over time. In some embodiments,however, it may be desirable to correct or accommodate for certainfactors, such as small offsets or biases and stochastic random signalvariations due to thermal and other effects.

In one embodiment, these biases may be addressed by placing the inertialsensing module 190 attached to the welding torch 26 in a calibrationdevice that causes a known acceleration (magnitude and direction) to beinput to the welding torch 26. For example, the calibration device maybe any device capable of holding the welding torch 26 substantiallystationary in one or more orientations in the earth's gravitationalfield. The calibration device may be heated to a steady statetemperature typically reached by the welding torch 26 during welding toreduce the effects of changing temperature during welding. Signals 196from the inertial sensing module 190 may be measured and comparedagainst the expected measurements. Indeed, a variety of methods andtechniques may be utilized to reduce or eliminate the likelihood of suchbiases affecting the travel speed calculation. For example, calibrationresults may be stored in the memory 86 of the travel speed monitoringdevice 52 as a mapping of inertial sensor module signals to expectedvalues. Upon receiving the signals 196 from the inertial sensing module190, the processor 76 may correct for any offsets or biases based on themapping stored in the memory 86.

Additionally, it should be noted that in certain embodiments, it may bedesirable to determine and monitor the travel speed of the welding torch26 over the total distance of the workpiece 14 being welded, and not thetotal distance travelled by the welding torch 26. That is, in instancesin which the operator 110 performs a weld in a traditional pattern, suchas weaving, the welding torch 26 may travel a large distance while onlycovering a small portion of the workpiece 14. If such a technique isused by the operator 110, the interpretation of the weld travel speedmay be adjusted to compensate for the weaving motion to derive thetravel speed along a travel direction (X) of the weld. Therefore, insome embodiments, the weld travel speed will not simply be the sum ofthe length of the weld vector. Instead, the algorithm for calculatingweld travel speed may continually determine the straight line or planardistance between a current weld location and some prior referencelocation and divide this distance by the elapsed weld time between thetwo locations. The elapsed time between points may be held constant, orthe initial reference point may be held constant at a weld initiationlocation. In some embodiments, the elapsed time between the twolocations may be adjusted to be a longer time interval when weaving isdetected.

In some embodiments, the distance between the current weld tip locationand the prior reference location may be calculated, for example, by thePythagorean Theorem if the displacements in the travel direction (X) andweave direction (Y) (or any two orthogonal directions on the weldsurface) is known. If this distance is found to be non-monotonicallyincreasing, then a weaving technique may be identified. Further, inembodiments in which a particular pattern (e.g., zigzag pattern) isbeing performed by the operator 110, the pattern may be identified byevaluating the excursions in the weave direction (Y) or the near lack oftravel in the travel direction (X) for some periods of time. The amountof weaving might also be detected by sensing the excursions in the weavedirection (Y). For example, in an embodiment, the time between thecurrent weld location and the prior reference location may be adjustedaccording to the amount of weaving detected (e.g., more weavingcorresponds to a longer time). Additionally, any low-pass filtering ortime averaging of the calculated travel speed may be adjusted (e.g.,more weaving corresponds to a longer time or lower frequency filter).

While only certain features of the invention have been illustrated anddescribed herein, many modifications and changes will occur to thoseskilled in the art. It is, therefore, to be understood that the appendedclaims are intended to cover all such modifications and changes as fallwithin the true spirit of the invention.

The invention claimed is:
 1. A system, comprising: a welding helmetcomprising a sensor system configured to detect a first position of afirst marking on a welding torch relative to the welding helmet, and todetect a second position of a second marking on a workpiece relative tothe welding helmet, and a display screen; and processing circuitryconfigured to determine a position of the welding torch relative to theworkpiece based at least in part on detection of the first and secondpositions of the first and second markings relative to the weldinghelmet, generate an augmented reality visualization based on theposition of the welding torch relative to the workpiece, and display theaugmented reality visualization on the display screen of the weldinghelmet.
 2. The system of claim 1, wherein the processing circuitry isconfigured to determine a travel speed of the welding torch parallel toa weld of the workpiece based on the position of the welding torchrelative to the workpiece.
 3. The system of claim 2, wherein theprocessing circuitry is configured to compensate for a weaving motionthat is not parallel to the weld of the workpiece when determining thetravel speed of the welding torch parallel to the weld of the workpiece.4. The system of claim 1, wherein the sensor system comprises an opticalsensor configured to detect the first marking on the welding torch, orthe second marking on the workpiece.
 5. The system of claim 3, whereinthe augmented reality visualization comprises a visual indicator thatindicates a travel speed of the welding tool.
 6. The system of claim 2,wherein the processing circuitry is configured to determine whether thetravel speed of the welding tool is too fast or too slow based on thetravel speed of the welding tool and a target travel speed, theaugmented reality visualization comprising a visual guide that indicateswhether the travel speed of the welding tool is too fast or too slow. 7.The system of claim 6, wherein the display screen is configured todisplay the visual guide overlaying a view of the workpiece seen throughthe welding helmet when the processing circuitry displays the augmentedreality visualization on the display screen of the welding helmet.
 8. Awelding system, comprising: a welding helmet comprising a sensor systemconfigured to detect a first marker position of a first marker of awelding tool, and a second marker position of a second marker of aworkpiece, the sensor system comprising an optical sensor, and a displayscreen; and processing circuitry configured to: generate an augmentedreality visualization based on the first marker position of the firstmarker of the welding tool, and the second marker position of the secondmarker of the workpiece, and display the augmented reality visualizationon the display screen of the welding helmet.
 9. The welding system ofclaim 8, wherein generating the augmented reality visualizationcomprises: determining a tool position or tool orientation of thewelding tool relative to the workpiece based on the first markerposition and second marker position, and generating the augmentedreality visualization based on the tool position or the tool orientationof the welding tool relative to the workpiece.
 10. The welding system ofclaim 9, wherein the processing circuitry is further configured todetermine a travel speed of the welding tool parallel to a weld of theworkpiece based on the tool position or the tool orientation of thewelding tool relative to the workpiece, the augmented realityvisualization comprising a visual indicator that indicates the travelspeed.
 11. The welding system of claim 10, wherein the processingcircuitry is further configured to compensate for a weaving motion thatis not parallel to the weld of the workpiece when determining the travelspeed of the welding tool parallel to the weld of the workpiece.
 12. Thewelding system of claim 9, wherein the processing circuitry is furtherconfigured to: determine a travel speed of the welding tool based on thetool position or the tool orientation of the welding tool relative tothe workpiece, and determine whether the travel speed of the weldingtool is too fast or too slow based on the travel speed of the weldingtool and a target travel speed, the augmented reality visualizationcomprising a visual guide that indicates whether the travel speed of thewelding tool is too fast or too slow, the display screen beingconfigured to display the visual guide overlaying a view of theworkpiece seen through the welding helmet when the processing circuitrydisplays the augmented reality visualization on the display screen. 13.The welding system of claim 12, further comprising a feedback sensorsystem configured to monitor a voltage or a current of a welding powersupply, the processing circuitry being configured to determine thetarget travel speed based on the voltage, the current, or a targetamount of heat to be provided to the workpiece.
 14. A method,comprising: detecting a first marker position of a first marker of awelding tool, and a second marker position of a second marker of aworkpiece, using a sensor system of a welding helmet, the sensor systemcomprising an optical sensor; generating, using processing circuitry, anaugmented reality visualization based on the first marker position ofthe first marker of the welding tool, and the second marker position ofthe second marker of the workpiece; and displaying the augmented realityvisualization on a display screen of the welding helmet.
 15. The methodof claim 14, wherein generating the augmented reality visualizationcomprises: determining a tool position or tool orientation of thewelding tool relative to the workpiece based on the first markerposition and second marker position; and generating the augmentedreality visualization based on the tool position or the tool orientationof the welding tool relative to the workpiece.
 16. The method of claim15, further comprising determining, using the processing circuitry, atravel speed of the welding tool parallel to a weld of the workpiecebased on the tool position or the tool orientation of the welding toolrelative to the workpiece, the augmented reality visualizationcomprising a visual indicator that indicates the travel speed.
 17. Themethod of claim 16, wherein a weaving motion of the welding tool that isnot parallel to the weld of the workpiece is compensated for whendetermining the travel speed of the welding tool parallel to the weld ofthe workpiece.
 18. The method of claim 15, further comprising:determining, using the processing circuitry, a travel speed of thewelding tool based on the tool position or the tool orientation of thewelding tool relative to the workpiece; and determining, using theprocessing circuitry, whether the travel speed of the welding tool istoo fast or too slow based on the travel speed of the welding tool and atarget travel speed; wherein the augmented reality visualizationcomprises a visual guide that indicates whether the travel speed of thewelding tool is too fast or too slow, and displaying the augmentedreality visualization on a display screen of the welding helmetcomprises displaying the visual guide overlaying a view of the workpieceseen through the welding helmet.
 19. The method of claim 18, furthercomprising: monitoring a voltage or a current of a welding power supplyusing a feedback sensor system; and determining the target travel speedbased on the voltage, the current, or a target amount of heat to beprovided to the workpiece.
 20. The method of claim 15, furthercomprising determining a welding quality parameter based on the toolposition or the tool orientation of the welding tool relative to theworkpiece, the welding quality parameter comprising a work angle of thewelding tool, a travel angle of the welding tool, a travel direction ofthe welding tool, or a distance between the workpiece and a tip of thewelding tool.